Pipe cutter



June 4, y1940. v 1 T ELLIS ,I 2,202,985

' PIPE CUTTER Filed May 22, 1939 if. VE- fri-5.2.I I

Patented June 4, 1940 UNITED STATES PATENT OFFICE PIPE CUTTER `.laines T. Ellis, Lake Charles, La.

'Application May 22, 1939, Serial No. 274,935

.10 Claims.

This invention relates tovpipe cutters, and has for its general object ,the provision of an im-v however, there has been no means of positively l' limiting the-amount of tension which can be exerted against the cutting knives during the cutting operation andv of maintaining this tensiony substantially constant ata predetermined value during-the cutting.

Itis therefore a more specific object of this invention to provide a cutting device of the type set forth in which an upward pull on the pipe carrying the cutting device will exert a tension on the `pipe to be cut in whatever amount may be 2'5 desired and will simultaneously urge the cutting knives toward cutting position with a `constant predetermined tension, which will vnot be increased-by the exertion of a greater pull upon the pipe to be cut. l n

Other objects and advantages of this invention will become apparent from the following description taken'in connection with the accompanying drawing, wherein is: set' forth by way of eX- ample and illustration one embodiment of thisA of In the drawing:

invention, showing in elevation a pipe about to be cut', the parts'being illustrated in the position which they occupy lbeforethe cutting operation begins.

Fig. 2 is a view similar to Fig. 1 but showing the partsin 'cutting position. n Fig. 3 isa horizontal cross section taken along 50- the line 3-3 of Fig. 2.

Fig. 4 is a horizontal cross section taken along the line 4--4 of Fig. 2. v

Fig. 5 is a horizontal cross section taken along the lined-5 of fFig. 2.

Fig. 1 is a vertical cross section through a cutter device constructed in accordance with this Referringlnow' more in detail to the drawing,

the numeral I designates a section of pipe which is to be cut. It will be understood that in the usual `conditions under which this invention will be employed, the pipe I will have become stuck in a hole so that it can not be withdrawn by ordinary pulling operations, and the present invention is utilized for the purpose of `cutting it off and withdrawing asection at a time. The pipe I which is to be cut may or may not have couplings or tool joints such as indicated by the numeral 2.

Referring now more specifically to the cutting device, the numeral 3 indicates a fitting which will be carried on the lower end of a string of pipe by which the cutting -device is lowered into the hole and operated. This fitting is internally threaded at its lower end as shown at 4 and is externally threaded' at 5 to receive the sleeve member 6 which constitutes the body of the cutter.

Within the sleeve 6 there is positioned an annular member 'I having depending integrally formed'slips 8 which are adapted as hereinafter described to grip the pipe to be cut, both during the cutting operation and during the removal of the pipe'from the well. The annular member 1 which may be referred to asa slip ring is eX- ternally threaded to engage the internal threads 4 in the tting 3.

Below the slips 8 the body 6 is provided with laterally opening slots 9 of a size adapted to receive cutting knives I0. These cutting knives Ill are pivotally mounted at I I in suitable slots in the lower end of a cutter carrier ring I2. 'Ihe upper end of the carrier ring I2 is provided with a suitable bearing surface I3 adapted to receive a similar bearing surface on a wedge ring I4. This wedge ring I4 is initially held in the position shown in Fig. l by means of a shear pin I5 so that it can move neither upwardly nor downwardly with respect to the body 6. During the time that the device is being lowered into a well, the knives Iii are held in their retracted position by means of binder screws I6 which bear against the Shanks of the cutter blades III in such a manner as to hold the blades themselves outwardly in inactive position.

Positioned below the lower ends of the blades lil ber 2U which extends up along the outside of the ring within each of the slots and has a bearing part hooked up over the edge of the ring and adapted to receive the lower ends of the respective knives. It will be seen that these bearing members 20 provide inclined surfaces for contact with the respective knives, which surfaces eX- tend from the outer wall of the body 6 to the inner wall of the ring Il. These elements 20 are secured to the ring I1 by any suitable means such as the screws 2|.

The ring Il and the cutter carrier I2 arel both permitted to slide vertically within the body 6 but are prevented from rotating within the body 6 by means of splines 22 formed in the body 6. The relative sliding movement of the cutter carrier I2 and the body 6 is limited by means of the cooperating shoulders 23 and 24 on the body and the cutter carrier respectively, so that the cutter carrier may not move toward the spring I8 by more than a predetermined amount.

It will be understood also that the wedge ring I4 is both rotatably and slidable within the body 6 once the shear pin I5 has been severed. Above this wedge ring I4 the body 6 is provided with an abutment 25 for a purpose which will presently be described.

In operation, the device is lowered into the well with the parts in the position shown in Fig. 1. When in this position, as previously explained, the binding screws I6 hold the knives in inoperative position. When in this position they are held against the bearing elements 20 so that the carrier ring I2 is prevented from moving downwardly within the body E. When the depth is reached at which the cut is to be made, the device is pulled upwardly a short distance. In those instances where the pipe to be cut has couplings or tool joints, the device will be pulled upwardly until the slips 8 engage such coupling or tool joint. Otherwise, the slips will be so formed as to engage the pipe itself. An upward pull is then exerted upon the device causing the wedge ring I 4 to engage the slips 8 and anchor them rmly against the pipe and a further upward pull will serve to shear the pins I5 and move the body 8 upwardly with respect to both the wedge ring I4 and the cutter carrier I2. This upward movement of the device with respect to the cutter carrier will cause the compression of the spring I8 until the binding screws I5 move above the upper ends of the knives, whereupon the knives will be moved inwardly by the bearing elements 23. Further upward pull on the body 6 will compress the spring I8 and move the body E upwardly with respect to the rings I2 and I4 until the shoulders 23 and 24 come in contact with each other. At this point, any additional upward pull on the device will be transmitted through the shoulders 23 and 24 and through the rings I2 and Ill directly to the slips and to the pipe to be cut, and no amount of additional pull will cause any additional compression of the spring I3 nor will it cause any additional force to be exerted upon the knives Ill tending to move them to cutting position. The parts are now in the position shown in Fig. 2.

The tool may now be rotated and as it is rotated the tension on the spring I8 will urge the knives against their work and cause them to cut the pipe. As heretofore stated, any additional tension placed upon the device will be transmitted directly to the pipe to be cut and will not increase the tension on the knives. A tension on the device is ordinarily maintained dur- ,4 in the fitting 3.

ing the cutting operation which will be sufcient to hold the device steady and cause it to perform its work efiiciently.

When the cut is complete, the severed portion of pipe may be removed from the hole by simply removing the cutter, this severed portion being held by the slips 8. During the cutting operation a tension may be taken on the pipe to be cut which is greater than the weight of the section that will be severed so that when the cut is completed there will be substantially no force exerted on the knives by the piece of pipe severed. Instead, as soon as the cut is completed this will be indicated to the operator by relief of the tension which he has been maintaining on the stuck pipe during this cutting operation.

In the event that it should be impossible to complete the cut for any reason, the cutting device here described may be released and withdrawn by iirst lowering the body 6 until the threads on the slip assembly 'I engage the threads Right hand rotation of the operating string will then cause engagement of these threads and move the slips upwardly with respect to the body 6. As the slips move upwardly, the upper end of the Wedge ring I4 will engage theabutment 25 and release this wedge ring from the slips. With the slips thus held up and out of engagement with the wedge ring hl the device may be withdrawn from the hole.

It will be seen from the foregoing that a device has been provided which is capable of being lowered into a hole and engaging a pipe and cutting the same. It will be seen that during the cutting operation as much tension as desired may be placed upon the pipe to be cut without placing any more tension than is necessary upon the knives which do the cutting. On the con trary, the knives which do the cutting will be urged toward their cutting position by a predetermined and substantially constant force and this force will be unaffected by the amount of tension exerted upon the pipe to be cut. It will also be seen that this device may be readily released and withdrawn in the event a completion of the cut is for any reason impossible. A device has therefore been provided which is capable of carrying out all of the objects and advantages sought by this invention.

Having described my invent-ion, I claim:

l. In an outside pipe cutter, a body, a cutter carrier slidably and non-rotatably carried by said body, cutter knives on said cutter carrier, which are inwardly movable, means for anchoring said carrier against longtitudinal movement with respect to a pipe to be cut, and resilient means carried by said body for resiliently urging said cutter knives inwardly into cutting position upon longitudinal movement of said body with respect to said carrier.

2. In an outside pipe cutter, a body, a cutter carrier slidably and nonrotatably carried by said body, cutter knives on said cutter carrier which are inwardly movable, means for anchoring said carrier against longitudinal movement with respect to a pipe to be cut, resilient means carried by said body for resiliently urging said cutter knives inwardly into cutting position upon longitudinal movement of said body with respect to said carrier, and means on said carrier and body for limiting such longitudinal movement.

3. In an outside pipe cutter, a body, a cutter carrier slidably and non-rotatably carried by said body, cutter knives on said carrier which are inwardly movable, means for anchoring said carrier against longitudinal movement with respect to a pipe to be cut, resilient means carried by said body for resiliently urging said cutter knives inwardly into cutting position upon longitudinal movement of said body with respect to said carrier, means for limiting such longitudinal movement, and means for transmitting force from said body directly to said carrier after the limit of such longitudinal movement has been reached.

4. In an outside pipe cutter, a body, a cutter carrier slidaby and non-rotatably carried by said body, cutter knives on said carrier which are inwardly movable, means for anchoring said carrier against upward movement with respect to a pipe to be cut, resilient means carried by said body for resilently urging said cutter knives inwardly into cutting position upon movement of said body upwardly with, respect to said carrier, means for limiting such longitudinal movement, and means for transmitting an upward force of said body directly to said carrier after such limit of movement has been reached.

5. In an outside pipe cutter, a body, a cutter carrier slidably and non-rotatably carried by said cutter body, cutter knives on said carrier which are inwardly movable, means for anchoring said carrier against longitudinal movement with respect to a pipe to be cut,'resilient means carried by said body for resiliently urging said cutter knives inwardly into cutting position upon longitudinal movement of said body with respect to said carrier, and means for holding said cutter knives in non-cutting position prior to such movement.

6. In an outside pipe cutter, a cylindrical cutter body, a cutter carrier slidably and non-rotatably carried by said cutter body, inwardly movable cutter knives on said carrier, means for anchoring said carrier against upward movement with respect to a pipe to be cut, and resilient means carried by said body for resiliently urging said cutter knives inwardly intocutting position upon longitudinal movement of said body with respect to'said carrier.

7. In an outside pipe cutter, a cylindrical cutter body, a cutter carrier slidably and non-rotatably carried by said cutter body, inwardly movable cutter knives on said carrier, means for anchoring said carrier against upward movement with respect to a pipe to be cut extending therethrough, and resilient means carried by said cutter body for resiliently urging said cutter knives inwardly into cutting position upon longitudinal movement of said body with respect to said carrier, and means for releasing said anchoring means from the pipe to be cut.

In an outside pipe cutter, anchoring means for engaging a pipe to be cut, a body movable with respect to said anchoring means to contact said anchoring means and transmit to said pipe to be cut any desired amount of force, cutter knives inwardly movable to cutting position, and means for applying a predetermined force to said knives urging them inwardly toward cutting position upon movement of said body into contact with said anchoring means.

9. In an outside pipe cutting device, means for engaging a pipe to be cut and applying a pulling force thereto, and including a lost motion connection, cutter knives movable inwardly to cutting position with respect to the pipe to be severed, and means operable upon take up of the slack in said lost motion connection to apply a predetermined force to said cutter knives urging them inwardly toward cutting position.

lll. In an outside pipe cutter, cutter knives movable inwardly to cutting position with respect to a pipe to be cut, means for engaging the portion of pipe to be severed and applying an unlimited pulling force thereto, means rotatable with respect to said pulling means for rotating said knives during the application of said force, means for applying a force to said knives urging them inwardly toward cutting position and means for limiting the amount of said force.

JAMES T. ELLIS. 

